Andy Roddick had new technology to thank on Thursday after he was put under pressure by British wildcard Alex Bogdanovic at Queen's.

The three-times former champion challenged an out call that would have put him match point down during the second set tiebreak.

The grasscourt tournament's Hawkeye technology ruled the ball had just clipped the line and Roddick went on to win the tiebreak 7-5 and the match 4-6 7-6 6-4 to reach the quarter-finals.

"I've always been a supporter of Hawkeye. There's a big difference between being down match point and up set point," he said.

"You don't want to walk off the court with a loss because you feel like it was maybe someone else's error besides the player," he added.

The technology, that allows the ball to be tracked with pinpoint accuracy, will be introduced at Wimbledon for the first time this year.

It is called into operation when players challenge a call they feel is wrong.

Roddick, twice a Wimbledon runner-up and ranked five in the world, was pushed all the way by the 117th ranked Bogdanovic who did not lose his serve until the seventh game of the final set.

"Today I probably didn't have my best stuff...but to get a win over a player who was playing well...that's a good feeling."

The American, who is coached by former Wimbledon champion Jimmy Connors, said he was kept on the back foot.

"I wasn't dictating play out there today. That bothered me. It was Jimmy's main concern," he said.

He added that, though he had been preparing for grass since the humiliation of being knocked out two weeks ago in the first round of the claycourt French Open, he was not thinking about Wimbledon, which starts on June 25, yet.

"We have the rest of the tournament here and an entire practice week," he said.